Speed drops

(Mikael Jonsson) #1

Choosing a gear and holding a steady cadence around 78-82 =  speed around 32 km/h for me.
For example in the start of the incline on KOM (Watopia reverse) my speed i steady but when the incline increases the speed goes down?
I´m using Tacx Bushido Smart and as the incline gets bigger the resistens gets harder and harder but still the speed drops even through the part that i still can hold the cadence.

A certain cadence at a specific gear should give the same speed uphill, only require more energy, or is there something I’m missing?

(Robin Boardman) #2

Take a look here and see if this helps:



(Eric C. (Zwift HQ)) #3

Hi Mikael,

The speed will go down because, well, you’re going up a hill. The amount of wattage you are generating is all we use to determine speed. 200 watts will definitely be faster on a flat than on a 11% incline, so change gears accordingly.

Additionally, like Robin posts, you can update your Bushido Smart and it will auto-adjust resistance based on incline in Zwift.

(Mikael Jonsson) #4

I’m bad at explaining myself in English, using Google Translate :wink:
My Bushido is updated and Zwift very much controls the resistance.

Let us for the sake assume this: gear 2:5, cadence 90rpm = 30km/h, incline 2% to 6%

With dumb-trainer: to maintain speed on the incline I have to increase the cadence to develop energy (watts) required for this.

With Bushido Smart: to maintain speed/cadence uphill I have to increase the force on the pedals due to Zwift increases the resistance on the Bushido.
As long Bushido’s breaking power is stronger then me (and it is) the speed should remain the same, but still speed drops some.

I reacted on this on a workout there I tried to keep a certain speed as long as possible. Not looking at the speedometer this isn’t something you notice.

I want You to know about this “issue” because otherwise Zwift feels very much like a irl-ride when you have a smart trainer.



(L Read) #5

With a smart trainer ( I am using computrainer) , the speed always drop going uphill unless you are greatly increasing you power output to compensate for the slope.  The greater the slope, the higher your power has to be to keep the same speed. 

(Mikael Jonsson) #6

OK, I give up, don’t think I can make U understand my point of view but I try one a last time.

one gear + one cadence = one speed
To maintain speed i have to inference power going uphill, more uphill = more power.
My trainer have more braking power than I can manage so in this case it must mean that Zwift can’t adjust my trainer to the right amount of breaking power for the slope and that’s why speed drops just like with dumb trainers to compensate but just very little.

Some thing else…
Looking forward to ride virtual Richmond 2015 UCI World Championship road course and to see what Zwift will present this autumn/winter.

Totally a Zwifter now U know only one (1) ride in irl with my racer this year, I rather go to the garage and Zwift :slight_smile:


(Ronald Termaat) #7

Agree with Mikael.

Holding the cadence and gear should hold the speed. But I am not sure if there is a possibility for Zwift to pick up the speed from a trainer. It can not know in which gear it is. If the trainer does give a rpm speed back (I use a Kickr) than that should be used for speed.

When you ride now the cadence (without shifting) can go down, while the speed goes up (and the power goes up). This feels unnatural.

Especially when climbing and you hit a flatter part, you can not hold the power even when there is a big increase in cadence. Therefore you do not really accelerate well. Although the rpm (of the wheel) shows a big increase in speed.

It would feel more natural if the speed was related to the rpm of the wheel, and not to the power.

(Christian Wiedmann [X] 50) #8

Mikael - have you set the trainer difficulty to 100% in the settings screen in Zwift? The default is 50%, meaning that your speed is significantly higher on the trainer than in Zwift when going uphill.

(Mikael Jonsson) #9

Thanks for the tip, I have now 100% an wow did it made difference in the hills, even more irl experience now and I loved it :slight_smile:

But still, cadence steady at 70rpm and still speed drops from 32 to 29 on a incline.
The gaming experience is good, absolutely but it feel like there is a little math issue. It’s simple for You to test this so when time allows maybe a fix, if not it’s still as I said a good game and i love it :-)   

Btw. I thought he was a smart trainer, everything would be handled by the software to all slulle have the same experience to the extent possible. With this attitude, I can adjust the resistance so it suits me best of high cadence o lower resistance or lower cadence o higher resistance.
There maybe a thought of this but as I said thought Zwift would make the experience as similar as possible to those with smart trainers.